If you go to the Dashboard -> Stacks & Blocks -> Global Areas (upper right dropdown) is the Header Navigation Global Area approved? (if not it will have a green approve button)

Is your cached turned off in Dashboard -> System & Settings -> Cache & Speed Settings? The cache should be turned off while you are doing development on the site. If it was previously turned on you should also Clear Cache from Dashboard -> System & Settings -> Clear Cache.

Many thanks for your reply, hutman.
I've cleared the cache and turned off the cache in all the different sections (Block, Theme CSS, CSS and JavaScript, Overrides and Full Page. I've also checked that there are no unapproved changes awaiting approval.
The problem persists, unfortunately.

Is it still using the auto nav block?
Do you have Pretty URLs turned on? If so, if you turn them off do the links work?
Can you provide a link to the site?

Thanks again, hutman.

The site is atwww.www.highamandrushdenu3a.org.uk....
As far as I know I don't have Pretty URLs turned on: one of the 3rd level pages I'm building is athttp://www.highamandrushdenu3a.org.uk/index.php/portfolio/aloud... (not very pretty!). You'll see from the site that I'm still using the original navigation block but have changed one page to "Groups" (although the name change is not reflected in the URL).

Jim

What I am seeing is that all of your pages, including the one you liked redirect back to index.php. Can you check in your website files that you don't have a .htaccess file in there somewhere that is doing redirects? The autonav has the correct links but the server is redirecting all of those links back to index.php for some reason.

Thank you yet again: sorry to be a pain.
I have one .htaccess file at the top level on my site, and it simply says:
. There is another in my public_html which says:
.
I'm afraid my knowledge of PHP is basic, to say the least. Am I likely to have yet another .htaccess lurking somewhere else?

That doesn't look like it would do it, but I can see using the Chrome Inspector that the URLhttp://www.highamandrushdenu3a.org.uk/index.php/services... is returning a Status Code:302 Found which means that it's being redirected. I can't really tell what would be redirecting it.

Thanks, hutman, and apologies for not saying so sooner: been away for a week or so. Appreciate your time even if you can't tell me exactly what stupid thing I've done!